The German Patent No. 1,593,657 discloses quaternary nitrogen-containing cellulose ethers, which correspond to the structural formula ##STR3## in which R.sub.Cell represents an anhydroglucose unit, y is a whole number from 200 to 5,000 and each R group represents a substituent of the following general formula: ##STR4## in which "a" and "b" are 2 or 3, m and p are whole numbers from 0 to 10, n is a whole number from 0 to 3, R.sub.1 represents a methyl or ethyl group, Q represents an anion and v is a whole number, which corresponds to the valence of Q. In the above formula, the average value of n per anhydroglucose unit of the cellulose ether is 0.1 to 0.5 and that of m+n+p is 0.1 to 2.5, with the exception of the cellulose ethers, for which the average value of m+p is equal to zero.
According to the claims of the patent, these ethers have an improved substantivity towards different substrates in comparison with unmodified cellulose ethers. They can therefore be used for purposes, for which the conventional cellulose ethers are not or not very suitable because of their nonionic or anionic character. The compounds can be used in cosmetic formulations.
The German Offenlegungsschrift No. 3,301,667 is directed to a method for the synthesis of cationic cellulose derivatives, which is characterized in that
(a) an alkali cellulose, suspended in an aqueous organic solvent that is at least partly miscible with water, is reacted with a nonionic etherification agent from the group consisting of glycide, glycide acetate or glycerin chlorohydrin in an amount of 2 to 10 moles/mole of anhydroglycose unit, PA1 (b) during or after the reaction, the reaction mixture is reacted with a cationic etherification agent of the general formula ##STR5## in which R represents a lower alkyl group with 1 to 4 carbon atoms or the group --N.sup.(+) R.sub.3 Cl.sup.(-) is replaced by a group ##STR6## in an amount of 0.5 to 2.0 moles/mole of anhydroglycose unit. PA1 R.sup.2 is a divalent aliphatic hydrocarbon group with 2 to 5 carbon atoms, PA1 R.sup.3, R.sup.4 are alkyl groups with 1 to 4 carbon atoms, PA1 R.sup.5 is an alkyl group with 1 to 4 carbon atoms or a benzyl group, PA1 X is a halogen or sulfate ester group or a sulfonic acid group, PA1 (a) an alkali salt of the carboxymethylcellulose is esterified at temperatures of 80.degree. to 170.degree. C., a pressure of 5 to 100 bar and a reaction time of 1 to 24 hours in a known manner with, based on the carboxymethyl groups, a 1- to 10-fold molar excess of alkyl chloride, the alkyl group of which has 1 to 3 carbon atoms, the excess alkyl chloride being removed from the reaction mixture in a known manner after the esterification, PA1 (b) the ester of the carboxymethylcellulose, thus obtained, is reacted with amines of the general formula ##STR9## in which R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are defined as in Formula I, at temperatures of 80.degree. to 150.degree. C., a reaction time of 1 to 10 hours and optionally at an elevated pressure in such amounts, that 1 to 10 moles of amine are used per mole of ester group. After the reaction, the excess amine is removed from the reaction mixture in a known manner, whereupon PA1 (c) the derivative of carboxymethylcellulose, thus obtained, which has tertiary amino group, is reacted optionally at an elevated temperature and optionally at an elevated pressure during a reaction time of 0.5 to 8 hours with, based on the tertiary amino groups, at least equimolar amounts of the compound R.sup.5 --X, in which R.sup.5 and X are as defined in Formula I.
It is pointed out in this Offenlegungsschrift that the known cationic conditioning agents (which also include the products of the German Patent No. 1,593,657) would have numerous deficiencies. For example, products with a good water solubility and a sufficient compatibility with anionic washing raw materials generally are not sufficiently active, so that a high dosage would be required. Other products of limited water solubility are too strongly substantive and are exhausted almost completely on the hair. After several treatments, this would lead to an accumulation and a decrease in the fullness and the set of the dried hair. The products of the German Offenlegungsschrift No. 3,301,667 would have these disadvantages to an appreciably lesser extent, if at all.
The German Offenlegungsschrift No. 3,502,833 discloses a cosmetic agent for the treatment of hair or skin, which contains a quaternary, macromolecular, polymeric compound derived from chitosan. The compounds are synthesized by reacting a chitosan, consisting of 50 to 100% deacetylated chitin, in the presence of a solvent with a glycidyl trialkylammonium halide and ethylene oxide in a suitable ratio. As starting material, especially chitosan, purified by reprecipitation, is used.
In the published European Patent Application No. 0 189 935, water-soluble cationic polysaccharides based on cellulose ethers are described, which differ from the compounds of the German Patent No. 1,593,657 essentially by additionally having an alkyl group with at least 8 carbon atoms. As a result, they are hydrophobically substituted.